In last weekend's Guardian Money you stated, in answer to a letter about energy bills: "Direct debit customers should always keep an eye on their balance as it is easy to end up vastly in credit. Energy companies will never offer to pay any of this back."

This sweeping statement seems rather unfair. On 31 December 2012 EDF advised me that my account was £260 in surplus and that they would be making a refund. By 4 January the money was in my bank account, and EDF has reduced my monthly payments from February. There are some good guys out there! I have no connections with EDF. AC,by email

In recent weeks we have had several letters like this, from people praising their energy provider, which was happy to pay back the account surplus – and several more from readers complaining they were refused. In some cases, the letters were from readers who were with the same firm. Ofgem should remind the power firms what the rules are governing direct debit surpluses. Back in 2009 it warned them to make "significant improvements" in the information provided to customers and refund policies, which were found to be "wholly inadequate". Clearly, more work needs to be done.

We welcome letters but cannot answer individually. Email us at consumer.champions@guardian.co.uk or write to Bachelor & Brignall, Money, the Guardian, 90 York Way, London N1 9GU. Please include a daytime phone number